Zinc-containing phosphate glasses
Patent 4940677 Issued on July 10, 1990. Estimated Expiration Date: 
December 26, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 26, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3215543 3248234 Phosphate glass for laser use Optical glass Alumina glass composition and magnetic head incorporating same Patent #: 4544974 InventorsAssigneeApplicationNo. 456550 filed on 12/26/1989US Classes:501/45, Phosphorus containing501/44, Fluorine and phosphorus containing501/47, And boron501/48And aluminum or berylliumExaminersPrimary: Bell, Mark L.Attorney, Agent or FirmInternational ClassesC03C 003/16C03C 003/17 C03C 003/19 C03C 003/247 AbstractThis invention is directed to the preparation of glasses exhibiting a transition temperature below 450° C., a working temperature below 500° C., and excellent resistance to attack by water and mild aqueous alkaline solutions. The glasses consist essentially, in mole percent, of at least 65% total of 23-55% ZnO, 28-40% P2 O5, and 10-35% R2 O, wherein R2 O consists of at least two alkali metal oxides in the indicated proportions selected from the group consisting of 0-25% Li2 O, 0-25% Na2 O, and 0-25% K2 O, and up to 35% total of optional ingredients in the indicated proportions selected from the group consisting of 0-6% Al2 O3, 0-8% B2 O3, 0-8% Al2 O3 +B2 O3, 0-15% Cu2 O, 0-5% F, 0-35% PbO, 0-35% SnO, 0-35% PbO+SnO, 0-5% ZrO2, 0-4% SiO2, and 0-15% MgO+CaO+SrO+BaO+MnO, consisting of 0-10% MgO, 0-10% CaO, 0-10% SrO, 0-12% BaO, and 0- 10% MnO. | |
